1. Field of the Invention
The invention herein generally relates to carpeting and, more particularly, to a tufted carpet and a means to prevent unraveling of the yarn in the tufted carpet.
2. Description of the Prior Art
U.S. Pat. No. 2,999,297 is representative of the prior art and really teaches away from the invention herein. The patent teaches the increasing of the tensile strength of the scrim threads. The scrim threads are made from wet strength paper ribboned and twisted into a thread. The threads are waxed to facilitate entry of the tufting needles. There is no weakening of any portion of the carpet structure.
U.S. Pat. Nos. 3,166,465 and 3,779,799 show the use of reinforcing coatings on the carpet backing to reduce tuft unraveling.
Finally, U.S. Pat. No. 3,293,110 teaches that polymeric fibers have been developed which have weak spots placed throughout the length thereof.
The approach towards the solving of the unraveling problem to date has been one of increasing the tuft bind to very high levels, that is, in the order of 20 pounds, in order to minimize the chance of pulling out long strands of yarn. While systems have been developed to achieve the high tuft binds required, they inevitably have some serious drawbacks, such as high cost, increased flammability and/or smoke generation. The invention herein is concerned with a novel approach towards the solving of the unraveling problem. The concept involves the treating of the back side of the carpet with an agent which will substantially lower the breaking strength of the yarn at the point of the backstitch. The face yarns or tufts are substantially unmodified. Consequently, only individual tufts will be pulled out from the carpet and not a strand of yarn.